"Jim Lesurf"

I have now produced a new webpage which looks at the way signals from CD,
can exceed the nominal 0dBFS level. The page is at

http://www.audiomisc.co.uk/HFN/OverTheTop/OTT.html

The material is an expanded form of what was previously published in the
August 2007 issue of Hi Fi News. It shows some examples of the waveforms
reconstructed from commercial CDs exceeding 0dBFS, and also shows a test
waveform that should (if reproduced without distortion) reach to above
+5dBFS.


** No exotic test waveform is needed to show the differences in peak
output capability between the various DtoA reconstruction filters. Just a
white noise signal that has been digitally generated by a random number
program ( M - sequence dither) does it fine. The Denon " Audio Technical
CD " has such a track (track 79).

When played on a variety of machines, the peak level as seen on a CRO varies
from the expected 2.8 volts on most modern CD and DVD players, up to 4 volts
peak on ones that use analogue reconstruction filters - like the Sony CDP
101.

Arny might like to include this interesting test in his pages.

I doubt it has the slightest audible effect on music program.



....... Phil